Lubricant and method of preparing same



June 27, 1944. s. LIEBER EIAL 2,352,213

LUBRICANT AND METHOD OF PREPARING SAME Filed Oct. 1, 1940. s Sheets-Sheet 1 EFFECT or 722% TING 3216!! T TOCK fl.

TAP/J FLO w June 27, 1944.

LUBRICANT AND METHOD OF PREPARING SAME E. LIEBER HAL 2,352,213

Filed Oct. 1, 1940 s sheets-sheet, 2

ASTM 7 602 June 27, 1944.

E. LIEBER ETAL LUBRICANT AND METHOD OF PREPARING SAME Filed'oct. 1, 1940 3 Sheets-Sheet 5 ASTM P00?- POINT 7-" FFT 0 flrknc rs orsPezvr cLAY P002 SENS/7'! V TI is 4 BLEND'WITH 6.05%

ETHYLENE CHLORIDE Exrzum-r 312w [0 2421's OF-BZIGHTSTOCKA 80 275 OF IVAEuTI AL OIL ll 0.2 O. 70 znrzcw clays which have been used the sensitivity of a lubricant invention 'neutral distillate nonmcan r mm MET-1 01101 PREPARING SAME man Bayonne, N. 1.. and

Company, a corporation of Dela- Application October 1, 1840,

Serial No. 359,190

8 Claim ((.1- 196-151) point of a lowered or small amount of a by condensing chlorinated parailln wax naphthalene in the presence of aluminum chloride as catalyst.

The present invention results from the discovery of the peculiar fact that spent or exha for clay treatins percolation of ce which increasing especially a blend of a neutral oil and a Bright Stock, in which it is dissolved, to a reduction in pour point upon addition of a synthetic pour depressor such as the type mentioned above. This is a peculiar phenomenon because, in many instances, this substance, which for-want of a better name wil be referred to as a susceptibility improver or pour sensitizer does not actually reduce the pour point itself but merely increases the effectiveness of synthetic pour depressors which are added to blends containing this improver. This is, to some extent, contrary to various teachings of the prior art.

therefore, the present invention comprises a lubricant comprising a waxy mineral of a synthetic and a small amount of a natural pour sensitizer extracted from a petroleum hydrocarbon fraction, preferably a crude petroleum distillation bottoms. by suitable means by clay treating. The preferred method of incorporating this pour sensitizer into the lubricant is to prepare a.naphtha solution of a portion of the lubricating oil to be'used, preferably a Bright Stock, and then-percolate this solution through the spent clay which has been used for clay treating a crude cylinder oil stock, and then has the unexpected characteristics of pour depressor,

Stock with any other lubricating oil stock to be used in the final blend. The pour depressor may either the treated Bright Stock after removal of the solvent be added to any other oil such as a neutral oil, to be used in the final blend.

Although the above method of incorporating the pour sensitizer into the lubricant is preferred, because-it produces a lubricant color and stability and substantially as good and even in some cases better quality as far as pour thio point reduction is concerned, howeve other methods may be used, for instance, extracting the pour sensitizer from the spent clay by a volatile solvent such as benzene, removing the solresultant extract which is containing our "pour sensitizer" as the experimental data will show below, to the Bright Stock or other mineral lubricating oil or blend to be used.

The spent clay to be used as the source of the pour sensitizer may be a clay which has been used for clay treating a crude cylinder oil stock preferably from aPennsylvania type crude, although other crudes such as the Colombia crude of the naphthenic base type, or mixed base. crudes may be used The clay treating may be accomplished by any known method, such as per-- colation, or by clay contacting by which is meant dispersing the clay throughout the oil at the desired temperature and then separating the clay by suitable means such as by settling, filtering,

such as centrifuging, etc. The temperature at which the clay treating should be carried out should be between the approximate limits of +50 and +250 F. Room temperature has been used. with clay treating should be approximately that required to impart to the crude cylinder oil of at least 1 or 2 Robinson.

After the clay treating has the spent clay may be either and preferably, is washed substantially free of oil by rinsing with fresh naphtha, such as by percolating naphtha through the clay.

If the pour sensitizer in the spent clay is to be incorporated in the Bright Stock by direct contact as suggested above and which is our preferred method, Stock is preferably dissolved in l to 10 volumes, usually 2 to 5 volumes are sufilcient, of a volatile solvent such as naphtha and then percolated, at room temperature through the spent clay which has been prepared as described above. The clay may be freed of adhering oil by rinsing with naphtha and the resultant washing may be combined the naphtha solution. percolate may be freed of solvent by distillation, e. g. on a water bath, preferably at reduced pressure, e. g. about 5 mm. absolute pressure. The temperature of this evaporation should preferably not exceed about 212 F. The treated Bright Stock thus obtained is ready for addition of the synthetic pour depressor to be used, together with any other oils to be blended therewith.

0n the other hand,vif it is not desired to contact the spent clay directly with the Bright Stock to be used in, the finished lubricant, the

spentclay, prepared as described above,may he been completed used as such or,

2,352,213 UNITED STATESPATENT OFFICE from the exhausted clay, washing the treated clays These solvents should be heated to a temperature not higher than about 150 F'. to 200 F., although room temperature may .be used, if desired. The extraction of the spent clay with the hot solvent is preferably continued until the drainings are substantially water white. The volatile solvent is then removed under vacuum, with some heating, if desired, although not at a temperature above about 212 F. The resulting extract is then diswhich is the pour sensitizer, being about 0.1% to by weight on the amount of Bright Stock, or about 01-10% on the finished lubricant.

containing preferably about 10% to of chlo: rine, with a suitable aromatic compound such about 13 to 15 parts by by fire and steam up to a temperature of about 500 F. or 600 F. However, other synthetic pour depressors known to the art may be used if desired such as those described in patents; U. S. 2.018.758; 2,055,482; 2,087,682; 2,106,247; 2,115,823,- 246; 2,201,767; 2,053,853; 2,061,008; 2,077,068; 2,111,769; 2,114,- 812; 2,118,772; 2,130,024.

The amount to be used however, it

to 10.0% and generally between the somewhat narrower limits of The invention appears to have its greatest effectiveness when the amount of synthetic pour depressor used is less than 0.5%,

amount of pour depressor used is even less than 0.2% (by weight on the finished lubricant).

The accompanying drawings illustrate graphically the application of our invention.

The invention will be better understood from the following experimental data:

EXAMPLE 1 cal data of the Pennsylvania crude bottoms were as follows: i

1 Average value.

250 grams of the Attapulgas clay were placed a percolation tube solvent) became a number 2 color on the Robinson scale. This required on the average 1 gram of fresh clay per gram of crude distillation bottoms. The spent clay was then washed free of In this series of tests, two different Bright Stocks were used, referred to herein as A and B. Bright Stock A had a pour point of +20 F. and B had a pour obtained from one refine and neutral B having a viscosity of 150 seconds Saybolt at 100 F. and a pour point of +25 F. and obtained from'a different refinery.

In carrying out these tests the Bright Stock was taken up in 4 parts by chloride, and a condensation temperature of at least -100 F. The experimental data obtained are summarized in Table 2.

Tan 2 r Treatment Bright Stocks with spent clay Pours on 10% m n. s.+00% as t as m added w de n Test No. by 33,, J Neutral A A +00 +15 -s -m 40 --20 A A +20 -10 -10 -a0 40 --2s A A 0 10 -15 -a0 -z0 2 .-do- A A as -s --10 -10 -a0 -a0 a A e +25 --5 -15 -20 -zs 4 Pennsylvanim A B +5 5 -l0 l5 +1) '25 a Colombian.. A A +25 +5 o Blank =1; A +25 +10 0 -10 -a0 7 Pennsylvania. B A m 6 -10 10 s Blank a B +5 0 -10 -15 40 9 Pennsylvania. B B +26 0 -10 -s0 20 10 Blankonlfioneutralaloneu nh +25 +10 0 -10\ --15 --20 I Second pm through spent clay used in Test 10.

From the data in the above Table 2 it is 011- served that the pour points or the neutral blends, without pour depressor, are practically the same as the original neutral 011. However, the neutral blend containing the treated Bright Stocks Pour oint-W. of

Bright Stock Original +20 +15 Treated +40 +20 As already indicated from the data in Table 2 that, with one exception, the treated Bright Stocks-neutral blend, without pour depressor, have substantially the same pour point as the neutral oil alone. One exception, however, was noted in Test 4 where the pour point of the neutral oil was +25 F. and the pour point of the Bright Stock was +40 F. but the blend of 90% neutral and 10% Bright Stock was +5 F. This is quite unexpected,especially since the untreated Bright' Stock alone had a pour point of +20 F. so that even though the treatment of the Bright Stock raised the pour point from +20 F. to +40 F., the blending with the neutral gave a substantial reduction in pour point,

down to +5 F. instead-0f +25 F.

It is also noted from Table 2 that the spent clay used for treating the Colombian crude bottoms yielded a somewhat lesssspotent. Bright Stock A than that obtained by percolating the same Bright Stock through clay: that had been used for treating a Pennsylvania crude.

1 It will also be noted by comparing Tests 0 an 1 in Table 2 that thetreated Bright Stock (in Test 1--A effected the greatest decrease in pour point when 0.1% ofpour depressor was used), namely, from-+15 to -:l0 ;F., a lowering of the pour point by 25 degrees whereas with larger-ali-v ditions ot'pour depressor, erg. 0.2% to 0.6%, although'the actual pourpoint was-lower, the difierence in pour point between that-with the .un-

Stock (comparing Tests 0 and 1-A) was only about 5 degrees. These results are set forth graphically in Fig. 1 which emphasizes clearly the advantages of this invention.

Similarly, with Bright Stock B in Tests 6 and '1 the greatest diflerence in pour point occurred with the use or 0.1% of pour depressor, thus indicating that the invention is especially useful for amounts of pour depressor less than 0.2%. The results of these Tests 6 and '1 are set forth graphically inFig. 2.

EXAMPIE 2 For another test, 500 cc. of Pennsylvania crud bottoms, dissolved in 1500 cc. of a refined naphtha marketed under trade name Varsol, which was clay percolated before use, were percolated through three successive 200 gram portions of Number 1 freshlyactivated 'Attapulgas clay. The filtrate, after removal of the solvent, yielded 420 cc. of stock having a No. 1 Robinson color and having a pour point of +90 F. (This is an increase of +50 F. over the original stock.) This yield of clay-percolated oil amounted to 84% of the original. The spent clay, after washing with light naphtha, was placed in a Soxhlet with hot benllol until the draining ran water white. The benzol was then removed under high vacuum on a water bath at a temperature notexceeding 212 F. 65

cc. (13% by volume) of a very viscous black oil was obtained as distillation residue, thus indicating that whereas the spent clay had at first contained about 16% of the original Pennsylvania crude bottoms, after the extraction with hot benzol, the spent clay only retains about 3% of the original Pennsylvania crude bottoms. This viscous black oil extract, containing the "pour sensitizer" of this invention, was blended with the same Bright Stock A used in the previous test, and the pour points ofthe resulting blends were determined'as follows:

Pour] point, F Bright Stock A +20 Bright Stock A I-0.5% extract (pour 1 The same pour depressor as used in i'lxample 1. I

It is noted that the extract, which contains the pour sensitizer has no eflect at all on the pour point of the Bright Stock, when added thereto in concentrations of from 0.5% to 2%. The last test in Table 3 was added merely. to show that the addition of a true pour depressor does reduce the pour points of this same Bright Stock, 0.5% of the pour depressor reducing it from 20 F. to F. It should be noted that the extract causeda considerable darkening of the Bright Stock A into which it was blended; and since in the previous procedure (Example 1) no change in color of the Bright Stock was eflected, this leads to the conclusion that the extract contains the novel pour sensitizer and that the Stock A containing 0.5% (by weight) of the benzol extract of the spent clay, were blended in 90 parts by volume of neutral A. This corresponds to 0.05% of the benzol extract in the finished blend. Pour points, with and without pour depressor (the same one as used in Example 1),

were then determined, the data obtained bein shown in Table 4.

EXAMPLE 3 A large quantity of No. 1 fresh Attapulgas clay was spent by percolating Pennsylvania crude bottoms through it in the same manner as described above. This spent clay was then divided into aliquot portions and extracted in a Soxhlet extraction apparatus with hot solvent until the drainings ran clear, using ethylene dichloride, acetone, ethylether and isopropyl alcohol respectively as the solvents. The yields of extracts from 300 grams of spent clay (using approximately the same ratio of crude bottoms to clay as in Example 2') for each solvent were approximately the same, namely, about 12 grams.

Each extract was tested for true pour depressing properties, as was done in Example 2, namely, by adding 0.5%, 1.0%, and 2.0%, respectively, of each different extract to the Bright Stock A, having an original pour point of +20 F., but in every single case the pour point of the Bright Stock containing the small addition of extract was identically the same, namely, +20 F. This TABLE 4 shows that none of the extracts had any pourreducing effect on this Bright Stock. mims'op. These same extracts were then made up in Per cent pour depressor blends with 10 volumes of Bright Stock and 90 added to 0 10% mmd Rs, A" volumes of neutral A, using three different 90%180neut-A 90%180nwLA amounts, namely, 0.05%, 0.10%, and 0.20% of each extract in the final blend, and then the pour 8-? if; 8 points of these blends were determined with and j jjjjjjijjf' j' j without addition of pour depressor (the one used in Example 1). The results are shown in the following Table 5.

\ TABLE 5 Pour points, F., per cent Solvent used for extraction gt 'gg pout depressor l None None +30 +15 -5 -15 20 Ethylene dichloride 0.05 +25 5 -10 -15 -20 ll Isopropyl alcohol 0.05 +25 +10 -10 -15 -20 l2 d0 0.10 +25 +10 -10 -15 20 13 .do 0.20 +25 0 -10 -20 -20 It is noted from these results in Table 4 that the treated Bright Stock A (containing the pour sensitizer) did not reduce the 30 F. pour point of the bright stock neutral blend when no pour depressor was used; on the other hand, the addition of 0.1% of pour depressor caused a remarkable change in the results, effecting a 30 reduction in pour point in the blend containing the treated Bright Stock but only a 15 reduction in pour point in the blend not containing any of the pour sensitizer. With larger additions of pour depressor, this pour sensitizing effect continues, although to a less noticeable extent.

It is remarkable to observe the results in Table 65 5 that the pour points of all of the blends, Tests and isopropyl alcohol were quite efiective when used in the larger amounts, e. g. 0.2%, but not so effective in the small amounts, such as 0.05%. The most surprising result of all was in Test 2 where 0.05% of pour sensitizer obtained by extracting the spent clay with ethylene dichloride Fig. 3.

In comparing the two methods of sensitizing oils to pour depressors discussed above, it should be kept in mind that they differ in several respects. Thus, the more direct method of percolating the Bright Stock itself (in naphtha solution) through the spent clay yields a product which, while it sometimes increases in pour point, has suffered no change in color. The clay extracts, on the other hand, markedly darken the oils into which they are blended.

Although the theory of the mechanism of the operation of the present invention is not at all understood, the results are clear and certain, and are highly unexpected, especially in the range of low concentrations of pour depressor.

It is not intended that this invention be limited by the specific examples which have been given here merely for the sake of illustration nor by any theory as to the mechanism of the operation of the invention, but only by the appended claims in which it is intended to claim all novelty inherent in the invention as broadly as the prior art permits.

We claim:

1. A lubricant comprising a waxy mineral lubricating oil, a small amount of synthetic pour depressor, and a small amount of natural pour sensitizer extracted from a crude petroleum distillation bottoms by clay treating.

2. Composition according to claim 1 in which the mineral lubricating oil is a blend of a lubricating oil distillate and a refined residual.

3. Composition according to claim 1 in which the pour depressor is made by condensing long aliphatic hydrocarbon chains onto an aromatic nucleus.

4. A lubricating oil composition comprising a major proportion of waxy mineral lubricating oil containing about to by volume of refined lubricating oil distillate having a viscosity of about -1000 seconds Saybolt at 100 F., and about 50 to 5% by volume of Bright Stock, said composition also containing about 0.01%- 5.0% by weight of the total blend of a pour depressor made by condensing chlorinated paraifin wax with naphthalene in the presence of aluminum chloride, and also containing a small amount of a pour sensitizer extracted from a crude cylinder stock by clay treating.

5. Composition according to claim 4, in which the pour sensitizer has been removed from the clay used for said clay treating by contacting said clay with a naphtha solution of at least a portion of the Bright Stock to be used in the finished lubricating oil composition.

6; Composition according to claim 4, in which 7 the pour sensitizer has been removed from the clay used for the clay treating, by extraction of said spent clay by a volatile solvent, separated from said solvent by distillation at a temperature not substantially above 212 F., and then dissolved in the lubricant to the extent of about 0.0l%-1.0% by weight on the finished blend.

7. Composition according to claim 4, in which the pour sensitizer was obtained from a Pennsylvania type crude oil stock.

8. The process of preparing lubricating oil compositions which comprises percolating Pennsylvania crude petroleum distillation bottoms through freshly activated Attapulgas clay, washing the resultant spent clay with a small amount of naphtha, then contacting the residual washed spent clay with a naphtha solution of Bright Stock to permit said Bright Stock solution to dissolve some of the constituents present in the spent clay having pour sensitizing properties, removing the naphtha from said Bright Stock solution and blending said treated Bright Stock with a lower viscosity refined lubricating oil distillate, and also incorporating in the finished blend a small amount of synthetic pour depressor.

- EUGENE LIEBER.

MARTIN M. SADLON. ALOYSIUS F. CASHMAN. 

